The invention relates to a vehicle having a device for setting an open position of a tailgate which can be pivoted upwards, and a method of operating the vehicle.
German Patent document DE 10 2008 011 637 A1, for example, describes a device for setting an open position of a tailgate which can be pivoted upward. The tailgate, after the manual or motor-driven opening of a lock that locks the closed tailgate, can be adjusted to one preset open position and, by way of an operating device, can be adjusted to another open position.
It is an object of the invention to provide a device for setting an open position of a tailgate of a motor vehicle which can be pivoted upwards, and which prevents a collision with objects or persons as well as facilitates loading of the tailgate compartment.
This and other objects are achieved by a vehicle according to the invention having a device for setting an open position of a tailgate which can be pivoted upwards and which, upon an opening command to a first control unit, can be adjusted to a predefined open position by way of an adjusting device. Furthermore, the vehicle has a device for setting a predefined vehicle height, which comprises a second control unit for actuating an active wheel suspension system. By way of a communication connection between the first control unit and the second control unit and by way of a corresponding programming of at least one of the two control units, also a lowering of the vehicle height is carried out during the opening of the tailgate. This takes place either in a direct sequence, in which case first an opening of the tailgate and, subsequently, a lowering of the vehicle height is carried out, or, particularly advantageously in a simultaneous manner.
Preferably, the lowering of the vehicle height with an opening of the tailgate is prevented when a blocking command for this function is present in at least one of the two control units. As a result, electric energy may be saved, if necessary.
In a further aspect of the invention, the lowering of the vehicle height with an operating of the tailgate is prevented when a blocking command for this function is present in at least one of the two control units such that no activation signal for this function was output by a certain operating element. Such an operating element may, for example, be a key button of a remote control, a separate switch in the luggage compartment or a selectable menu item in a vehicle computer (such as the iDrive by BMW).
When the operating element is actuated for the output of the activation signal while the vehicle is not yet lowered, starting from an open position of the tailgate, a further opening of the tailgate preferably takes place by the amount by which, after the simultaneous or directly following lowering of the vehicle height, the same sheltering height is achieved as before the actuation of the operating element.
The invention is based on the following considerations. For example, from German Patent document DE 195 25 835 A1, a device is known for setting a vehicle height in the form of a wheel suspension control system for motor vehicles by defining a desired distance of a wheel from the vehicle body. However, wheel suspension control systems are basically more likely to be used for interventions controlling the driving dynamics.
By use of the existing wheel suspension control system, however, as a result of their multifunctional use, simultaneously with the opening of the tailgate, a lowering of the vehicle can be made possible. This facilitates loading, in particular of vehicles with a high loading edge.
The position of the loading edge is often too high, particularly in the case of comfortable sport utility vehicles (SUVs), especially when loading heavy objects, so that a loading can only be carried out with great effort and under ergonomically unfavorable conditions. A lowering of the vehicle, for example, by way of an active air suspension of a wheel suspension control system either only in the rear area, or completely, constitutes a remedy in this case. However, the lowering of the vehicle has the result that the head sheltering height under the open tailgate is also reduced. Therefore, preferably simultaneously with the lowering of the vehicle, the opening angle of the tailgate is increased in order to, for example, maintain or reset the original head sheltering height.
The simultaneous adjustment of the tailgate as well as of the vehicle height prevents an earlier increase of the opening angle from generating a collision risk in the upward direction, and a later increase of the opening angle from causing a risk of injury to the loading person.
After the loading of the luggage compartment, at least the raising of the vehicle can be initialized by way of a manual actuating device and the vehicle can be returned to its original height level. In addition or as an alternative, the raising of the vehicle height automatically takes place at the start of the drive, for example, with the start of the drive motor. In order to prevent risk of damage, for example, as a result of a collision with a garage ceiling, preferably the height of the previously increasingly opened tailgate will also be reduced again to the original value. This is ideally carried out again synchronously with the raising of the vehicle height. However, if the tailgate is closed manually before the vehicle is returned to the original vehicle height, the simultaneous automatic adjustment of the tailgate will not take place.
The above-described exemplary method according to the invention is preferably implemented by at least one corresponding program module in at least one control unit which is basically responsible in a known manner for the device for setting the tailgate and/or for the device for setting a predefined vehicle height by use of corresponding actuators and sensors. If several control units are used, these interact by use of corresponding communication modules.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.